Surely I’m not the only person who would like to see Ubuntu be able to run inside a container with at least init, systemd, and systemctl functionality. I need a purpose built container with Ubuntu 22.04 in order to run a single application. That application requires at least basic Ubuntu functionality. Is that too much to ask? 
I know you can build a container with a supposed Ubuntu image pulled from the Docker Hub. But is it really Ubuntu? After I RDP into the container and have a look around, start a terminal, update and upgrade the system, start Firefox, and download the application I need to use in the container, it isn’t capable of installing the app because this “Ubuntu” doesn’t have a “services manager”. To me it seems abundantly clear that there needs to be some way to run at least a single application inside a container.
You ask, why not use a VM instead of a container? 
Well yes, VMs can handle that with no problem. But, VMs hog scarce resources that have to be completely allocated to them even when they aren’t using them. Containers on the other hand don’t have to hog huge amounts of memory with the OS kernel software. They also have full use of all available host resources when needed and very little when it is not needed. With that kind of flexibility it seems to me that people would be falling over themselves to develop that kind of functionality from a container. But alas, there is practically no information I could find on this topic except.
lxc - Start full container in Docker? - Stack Overflow
and
How can I run a full OS in a Docker container, without specifying a command? - Server Fault
These posts are 10 years old and didn’t have information that was helpful to my situation. Surely progress has been made on this problem within 10 years.
Does anybody have insight on how I can get what I need from a container?